Dust collectors that collect dust from an air to be processed have been known. As a dust collector of this type, Patent Document 1 discloses a dust collector using two grid-like electrodes.
The dust collector includes a first electrode, a second electrode, and a power supply for applying a voltage to both electrodes. The first electrode and the second electrode substantially have the same structures. Specifically, each of those electrodes includes a base having a grid structure, and protrusions protruding in the axial direction of the grid holes from the base. The protrusions are formed at the side end portions of the respective grid holes. That is, in those electrodes, there is a one-to-one correspondence between the side end portions of the grid holes and the protrusions. In the dust collector, the two electrodes are positioned to face each other, so that the protrusions of the first electrode are inserted into the grid holes of the second electrode, and the protrusions of the second electrode are inserted into the grid holes of the first electrode.
When a voltage is applied to both electrodes, an electric field is formed between the first electrode and the second electrode, and dust collecting surfaces for collecting dust from the air to be processed are formed on the surfaces of the first electrode. Specifically, as electric fields are formed between the inner peripheral faces of the grid holes of the first electrode and the protrusions of the second electrode, dust collecting surfaces are formed on the inner peripheral faces of the grid holes of the first electrode. Also, since an electric field is formed between the protrusions of the first electrode and the inner peripheral faces of the grid holes of the second electrode, dust collecting surfaces are formed on the outer peripheral faces of the protrusions of the first electrode. Dust in the air to be processed is drawn to and collected onto those dust collecting surfaces. As a result, the air to be processed is cleaned.